A tourist has come forward with the clip, which shows the moment the baby was separated from its herd while crossing a fast-moving river.

In the video, which is courtesy of Natalie Kinzel, it looked like the calf was facing certain death, but finds the strength to make it across. However, the effort leaves him exhausted and freezing.

The baby animal could barely stand as he huddled close to a car to get warm against the engine.

The bison made headlines when a tourist put him in the back of his SUV and brought him to a ranger station — saying he found the calf alone and shivering.

But animal experts like Corbin Maxey say it was the wrong thing to do.

"Humans do more harm trying to intervene with wildlife trying to save it. It is doing more harm than good," Maxey told Inside Edition. "I think Yellowstone officials did the most humane thing for this calf. It is a very sad story but it is better than letting this calf starve."